For every type of operation in the shop, no matter how simple or complex, there’s a way to screw it up. I’m not talking operator error, like cutting the wrong side of the line, gluing something out of square – or sanding through a veneer. There are screw-ups that you don’t even know about until you’ve, well, screwed it up.

Here are three examples, things I’m especially wary of – having experienced them at first hand.

Fine height adjuster on router unwinding in use – means you’ve unwittingly been routing progressively deeper and the only right piece is the first piece. (Similarly router collet not tight enough allowing bit to pull out on you)

The piece of paper put between the clamp and the work piece to prevent iron marks on your glue up – gets scrunched up between the boards when you tighten the clamps and is glued into the top or panel forever.

These are things I am extra vigilant about, but is there anything in particular you are extra wary of in your woodworking quests?

25 replies so far

I keep everything good side up as I’m milling pcs parts. I hate it when I turn a pc upside down and get the chip out, or the bad side to the inside or on the joint instead of a good clean joint. Face up for everything all the way up to the build.

I always draw up plans for my projects and make calculations, but I really only follow them in the beginning of the project. I feel it gets me started in the right direction and then from there, I measure as I go and design as I go. So my thing is following plans originally, but then letting the rest of the design evolve as I go. This is one reason I don’t like to build from premade plans. I have a hard time following them through to the end.

Depending on how large the project and glue up is, a glue up is not always permanent, it can be delaminated, by using a heat gun of 400 degrees or hotter and heating up the glue joint, (no matter how long cured) and using a metal scrapper working it between the glue joints along with heat it can be split apart with no damage to the wood only a little sanding to remove the glue left behind, any wood glue.

One of my peeves is not getting accurate box joints because not having the proper pin or project placement before making the cut.

A big screw-up is when you are setting the dado blade height on a table saw. You crank up the blade to find it is too high, so you crank it down a bit. When you do this, you introduce backlash in the blade elevating mechanism. When you run the saw, vibration will cause the blade to drop down a fraction; you end up with a dado that is not deep enough. This also happens with any blade. Always make final height adjustments while cranking UP, never down. The same goes for routers in a table. If you tilt the blade, make sure you return it to zero right after the cuts are made. I hate it when you cut a piece and find that you forget to zero the blade.

I am a great advocate for precision. My saw is set so that I’m always within .002” of my measurement. I know that kind of accuracy is hard to maintain in wood, but the fact is, the machine is capable of such accuracy and it’s the wood that changes; especially in soft woods. Whatever I’m making, I always make a test cut on scrap before commiting to the actual cut. An inexpensive digital caliper will give you all the precision you will ever need. I do all my woodworking the same as metalworking. Any changes in dimensions due to shrinkage or expansion, are much smaller.I also draw all my projects with Autocad software. This gives me exact dimensions, eliminating any errors in math.

Planning ahead. Like how to attach cleats on a narrow table or box that will not work with your cordless drill driver.

Not related to wood but I watched my HVAC guys install ducting. They have been doing it for decades yet still installed the returns in front of the supply, causing them to have to reach across the former to install the latter. I just shook my head.

Screw-ups reminds me of a cabinet installer I was working with years ago. We always used 2” screws to attach countertops to bases. This young man grabbed a 2 1/2” and put it through the mica top and well into his palm as he held the top down. He promptly dropped the screw gun and couldn’t remove himself from the top, it became my job to unscrew him and drive to the emergency room.